Static members of a class are not associated with any one particular instance/object of it. They can even be accessed without any instance. The way to refer to them in your code is as shown below:
static const std::string className;
static const std::string& getClassName()
std::cout << Test::getClassName();
It is also allowed to be able to access the static members via an instance/object as below: (modifying the above main function and keeping reset the same)
std::cout << testObject.getClassName();
Usually though, it is better to use the previous notation using the scope resolution operator (op '::'). That makes the code more readable in the sense that you know it is a static member and not a non-static one. It speaks for itself.